This invention relates to a firing device for a thyristor, and more particularly to such a device in which electrical energy required for firing a thyristor is supplied from a voltage applied across the anode and cathode terminals thereof.
Firing devices of the type referred to are advantageous in that their construction is simplified but disadvantageous in that to maintain the gate current or pulse at a predetermined magnitude and broaden the pulsewidth thereof inevitably leads to an increase in loss, and with the gate pulse required to broaden in pulsewidth, the time delay for refiring can not be decreased unless the loss is increased and so on.
It is an object of the present invention to provide a new and improved device for effectively firing the thyristor in various thyristor circuits including those necessarily using a wide gate pulse without an increase in loss.
It is another object of the present invention to provide a new and improved device for firing a thyristor with a simplified construction and without the necessity of separately providing means for supplying electrical energy for firing the thyristor.
It is still another object of the present invention to provide a new and improved device for firing a thyristor in which the supply of firing energy to the thyristor is isolated from the generation of a signal for controlling a firing time thereby to prevent malfunction due to noise.